Field of the Invention
The invention generally relates to a semiconductor device and a manufacturing method thereof. More particularly, the invention relates to a semiconductor sensing device and a manufacturing method thereof.
Description of Related Art
With the development of science and technology, semiconductors have been extensively applied to our daily lives. Among various types of applications of the semiconductors, gas sensing devices having the semiconductors have drawn more and more attention because the semiconductors are greatly sensitive to the gas which the semiconductors are in contact with. Specifically, after a gas sensing semiconductor is in contact with a specific gas, the electrical properties (e.g., the resistance) of the gas sensing semiconductor may correspondingly alter; therefore, through detecting and measuring the electrical properties of the gas sensing semiconductor, a user is able to determine whether said specific gas exists in the surroundings where the semiconductor is located.
When the semiconductor is applied to sense the gas, the measure of contact area between the semiconductor and the gas is a factor that directly contributes to the sensing sensitivity of the semiconductor; hence, an electrode covering the semiconductor lessens the sensing sensitivity of the semiconductor. In addition, the electrode electrically connected to the semiconductor may be designed to have the special structure according to the related art; alternatively, the electrode and the semiconductor may be composed of a plurality of microstructures, such that the contact area between the semiconductor and the gas can be expanded. However, gaps among the microstructures of the semiconductor are often filled with the microstructures (or the sub-structures) of the electrode while the microstructures (or the sub-structures) are formed, and thus the resultant structure is not satisfactory.